search for: ymms

Hi, What is the calling conventions for YMM. According to documents I saw till now, the YMMs are scratch and not saved in callee. This is also the default behavior of the Intel Compiler. In X86InstrControl.td the YMMs are not in "defs" set of call. - Elena --------------------------------------------------------------------- Intel Israel (74) Limited This e-mail and any atta...

I'll explain what we see in the code. 1. The caller saves XMM registers across the call if needed (according to DEFS definition). YMMs are not in the set, so caller does not take care. 2. The callee preserves XMMs but works with YMMs and clobbering them. 3. So after the call, the upper part of YMM is gone. - Elena -----Original Message----- From: Bruno Cardoso Lopes [mailto:bruno.cardoso at gmail.com] Sent: Monday, January 09,...

Hi, > What is the calling conventions for YMM. According to documents I saw till now, the YMMs are scratch and not saved in callee. > This is also the default behavior of the Intel Compiler. x86_64 Non-windows targets use the rules defined in the x86_64 abi! > In X86InstrControl.td the YMMs are not in "defs" set of call. The XMMs are subregisters of YMMs, and they are in t...

On Jan 8, 2012, at 11:18 PM, Demikhovsky, Elena wrote: > I'll explain what we see in the code. > 1. The caller saves XMM registers across the call if needed (according to DEFS definition). > YMMs are not in the set, so caller does not take care. This is not how the register allocator works. It saves the registers holding values, it doesn't care which alias is clobbered. Are you saying that only the xmm part of a ymm register gets spilled before a call? > 2. The callee preserves XM...

On Jan 9, 2012, at 10:00 AM, Jakob Stoklund Olesen wrote: > > On Jan 8, 2012, at 11:18 PM, Demikhovsky, Elena wrote: > >> I'll explain what we see in the code. >> 1. The caller saves XMM registers across the call if needed (according to DEFS definition). >> YMMs are not in the set, so caller does not take care. > > This is not how the register allocator works. It saves the registers holding values, it doesn't care which alias is clobbered. > > Are you saying that only the xmm part of a ymm register gets spilled before a call? > >&g...

...n AVX On Jan 9, 2012, at 10:00 AM, Jakob Stoklund Olesen wrote: > > On Jan 8, 2012, at 11:18 PM, Demikhovsky, Elena wrote: > >> I'll explain what we see in the code. >> 1. The caller saves XMM registers across the call if needed (according to DEFS definition). >> YMMs are not in the set, so caller does not take care. > > This is not how the register allocator works. It saves the registers holding values, it doesn't care which alias is clobbered. > > Are you saying that only the xmm part of a ymm register gets spilled before a call? > >&g...